Coal is one of fossil fuels. This coal itself is a sedimentary rock that can be burned and formed from organic deposits, mainly is plant remains and is formed through the process of pembatubaraan. This coal consists of carbon, hydrogen, and oxygen.
Coal requires certain conditions and only occurs in certain eras for its formation. According to researchers, the Carbon Age, which was approximately 340 million years ago, was the most productive time for coal formation, where almost all economical coal deposits in the northern hemisphere were formed. In addition to the Carbon Age, there are also Permian Ages which also form economical coal deposits in the southern hemisphere, such as Australia, and continue to the Tertiary Period (70-13 million years ago) in various other parts of the world.